Objectives: This study aimed to determine whether errors in vascular measurements would affect device selection in endovascular aortic repair (EVAR) by comparing measurements obtained using non-contrast computed tomog...Objectives: This study aimed to determine whether errors in vascular measurements would affect device selection in endovascular aortic repair (EVAR) by comparing measurements obtained using non-contrast computed tomography (NCT) with those obtained using contrast-enhanced CT (CECT). Materials and Methods: This single-center, retrospective study included 25 patients who underwent EVAR for abdominal aortic aneurysm at our institution. A 1-mm horizontal cross-sectional slice of NCT and CECT from each patient was retrospectively reviewed. The area from the abdominal aorta to the common iliac artery was divided into four zones. A centerline was created using the NCT by manually plotting the center points. Subsequently, the centerlines were automatically extracted and manually corrected during the arterial phase of CECT. The diameter and length of each zone were measured for each modality. The mean diameters and lengths of the target vessels were compared between NCT and CECT. Results: The measurements obtained using both methods were reproducible and demonstrated good agreement. The mean differences in vessel length and diameter measurements for each segment between NCT and CECT were not statistically significant, indicating good consistency. Conclusion: NCT may be useful for preoperative EVAR evaluation in patients with renal dysfunction or allergies to contrast agents.展开更多
根据全国海洋捕捞渔船换证数据库,运用现代软件工程的方法,介绍了海洋捕捞渔船分析系统(M arine F ish ing Vessel Analysis System,以下简称MFVAS)。首先从实际需求出发,分析了MFVAS的功能,如数据处理、统计分析、信息查询、报表打印...根据全国海洋捕捞渔船换证数据库,运用现代软件工程的方法,介绍了海洋捕捞渔船分析系统(M arine F ish ing Vessel Analysis System,以下简称MFVAS)。首先从实际需求出发,分析了MFVAS的功能,如数据处理、统计分析、信息查询、报表打印、系统管理等;其次介绍了MFVAS的系统设计,主要有系统结构设计、数据库设计、“层级”设计、图表设计等;同时简要说明了系统的实现,包括开发工具VB.NET、数据库系统SQL Server 2000等。最后概述了MFVAS的实际应用,指出了渔船管理存在的主要问题,同时讨论了MFVAS的发展趋势。展开更多
Sealing analysis of sealing system in reactor pressure vessels is relevant with multiple nonlinear coupled-field effects, so even large-scale commercial finite element software cannot finish the complicated analysis. ...Sealing analysis of sealing system in reactor pressure vessels is relevant with multiple nonlinear coupled-field effects, so even large-scale commercial finite element software cannot finish the complicated analysis. A finite element method of 3D transient coupled thermo-elastic-plastic contact sealing analysis for reactor pressure vessels is presented, in which the surface nonlinearity, material nonlinearity, transient heat transfer nonlinearity and multiple coupled effect are taken into account and the sealing equation is coupling solved in iterative procedure. At the same time, a computational analysis program is developed, which is applied in the sealing analysis of experimental reactor pressure vessel, and the numerical results are in good coincidence with the experimental resuits. This program is also successful in analyzing the practical problem in engineering.展开更多
文摘Objectives: This study aimed to determine whether errors in vascular measurements would affect device selection in endovascular aortic repair (EVAR) by comparing measurements obtained using non-contrast computed tomography (NCT) with those obtained using contrast-enhanced CT (CECT). Materials and Methods: This single-center, retrospective study included 25 patients who underwent EVAR for abdominal aortic aneurysm at our institution. A 1-mm horizontal cross-sectional slice of NCT and CECT from each patient was retrospectively reviewed. The area from the abdominal aorta to the common iliac artery was divided into four zones. A centerline was created using the NCT by manually plotting the center points. Subsequently, the centerlines were automatically extracted and manually corrected during the arterial phase of CECT. The diameter and length of each zone were measured for each modality. The mean diameters and lengths of the target vessels were compared between NCT and CECT. Results: The measurements obtained using both methods were reproducible and demonstrated good agreement. The mean differences in vessel length and diameter measurements for each segment between NCT and CECT were not statistically significant, indicating good consistency. Conclusion: NCT may be useful for preoperative EVAR evaluation in patients with renal dysfunction or allergies to contrast agents.
文摘根据全国海洋捕捞渔船换证数据库,运用现代软件工程的方法,介绍了海洋捕捞渔船分析系统(M arine F ish ing Vessel Analysis System,以下简称MFVAS)。首先从实际需求出发,分析了MFVAS的功能,如数据处理、统计分析、信息查询、报表打印、系统管理等;其次介绍了MFVAS的系统设计,主要有系统结构设计、数据库设计、“层级”设计、图表设计等;同时简要说明了系统的实现,包括开发工具VB.NET、数据库系统SQL Server 2000等。最后概述了MFVAS的实际应用,指出了渔船管理存在的主要问题,同时讨论了MFVAS的发展趋势。
文摘Sealing analysis of sealing system in reactor pressure vessels is relevant with multiple nonlinear coupled-field effects, so even large-scale commercial finite element software cannot finish the complicated analysis. A finite element method of 3D transient coupled thermo-elastic-plastic contact sealing analysis for reactor pressure vessels is presented, in which the surface nonlinearity, material nonlinearity, transient heat transfer nonlinearity and multiple coupled effect are taken into account and the sealing equation is coupling solved in iterative procedure. At the same time, a computational analysis program is developed, which is applied in the sealing analysis of experimental reactor pressure vessel, and the numerical results are in good coincidence with the experimental resuits. This program is also successful in analyzing the practical problem in engineering.
